a. Field of the Invention
The present invention pertains to data storage systems and specifically to data storage systems having multiple disk drives operable in a single device.
b. Description of the Background
Multiple disk drives are an essential component in today's large data storage systems. Often, multiple individual disk drives may be configured in many different storage systems including various RAID configurations. Each disk drive may be a single point of failure that may be individually replaced in the field.
For rack mounted disk arrays, only the front or back of a rack mounted box is generally available for access to the individual disk arrays. In order for a disk array to have replaceable components, it is desirable for all of the serviceable components to be accessible through the front or rear ends of the rack mounted unit. Thus, it is typical for the removable components to slide into the unit from the front or back. Further, it is generally desirable to have airflow through the rack mounted unit from front to back or back to front, since the top and bottom of the unit can be assumed to be blocked.
For each removable component, the connections for the component are generally arranged perpendicular to the axis of insertion and removal. Since a typical removable component for a rack mounted disk array has a large number of connections, a connector with a large number of pins is often required. When many removable components exist in the unit, a large number of connectors are typically mounted on a midplane printed circuit board that is perpendicular to the removable components.
The midplane printed circuit board may have connectors on one side that face the removable components and connectors on the opposite side that connect to other interfaces. The midplane board poses several problems for a designer. First, the board can be a single point of failure for the entire rack mounted unit. Second the midplane board often poses substantial restrictions on airflow, since the midplane board is generally oriented perpendicular to the conventional airflow through a rack mounted box. Similar restrictions and shortcomings exist when the unit is configured as a desktop, benchtop, or other type of packaging.
In a rack mounted disk array with replaceable drives, only the front of the rack mounted case is generally used for the removal and replacement of the failed components. The depth of a rack mounted case may be 18 or more inches deep, yet a removable disk drive mounted on a carrier may be 6 inches deep, leaving a significant amount of room that cannot be used for removable disk drives. Often, such space is used for power supplies, controllers, and other such functional equipment.
It would therefore be advantageous to provide a system and method for mounting a plurality of disk drives in a replaceable, serviceable manner that eliminates the airflow restrictions of the conventional midplane printed circuit board. It would be further advantageous to provide a system and method provides for higher data storage per rack mounted unit than is possible with other disk array systems.